Introduction

To assist the users with various operations performed on the computer, Microsoft Windows provides various pre-created dialog boxes. In all cases, these are fully-functional dialog boxes but sometimes they are difficult to use or customize. Programming environments and libraries such as the VCL sometimes provide their own implementation of these dialog boxes. We will review some of those dialog boxes. When a dialog box is available in the VCL, we will prefer that version. If not, then we will have to use the version available in Win32.

If you want to display the operating system's About box, you can call the ShellAbout() function of the Win32 library. Its syntax is:

int ShellAbout(
  __in_opt  HWND hWnd,
  __in      LPCTSTR szApp,
  __in_opt  LPCTSTR szOtherStuff,
  __in_opt  HICON hIcon
);

The first argument is a handle to the object that is calling the dialog box. The second argument is the title that will display on the title bar. This string would start with About when it displays. The third argument is a string to display below the copyright message. Here is an example of calling this function:

//---------------------------------------------------------------------------
void __fastcall TForm1::btnAboutClick(TObject *Sender)
{
    ShellAbout(Handle,
	       "About College Park Auto Repair",
	       "Commercial Authoriry",
	       NULL);
}
//---------------------------------------------------------------------------